ZODTTD who released a private beta of his Gameboy Advance emulator gpSPhone v1.2.0 two days ago, has made it now public. You can grab it from his page.

Changes:

– Added initial support for .zip archived .gba files. The .zip must ONLY contain a single .gba file.
– Added support for volume changing via iPhone and iTouch volume controls.
– Added option to add a new savestate file or overwrite the previously loaded one.
– Improved save state support. No more crashes and save states are timestamped. Compatibility remains for old version savestates.
– Improved suspending/resuming of the emulator.
– Improved button input routine. Now combo buttons work better.
– Improved the default skin/overlay to support better left and right button input.
– Fixed a bug causing the emulator to crash when headphone jacks were inserted or removed during gameplay.
– Fixed a delete ROMs bug.
– Fixed a bug in the controller skins that made L+R goto the menu screen.
– Moved the unscaled GBA screen to the top of the actual screen.
– Increased performance.

http://zodttd.com/forum/index.php?topic=435.0